The following problem is a classic homework assignment that I first saw when taking classes at Iowa State University. While it has been adapted here into a three dimensional foldable aquifer model the basic problem is still the same.
The purpose of this problem is to investigate how hydraulic conductivity and aquifer thickness are related. After folding the aquifer the equipotential lines on the top of the model are meant to represent the the total head in the aquifer for both the Sand/Gravel aquifer of uniform thickness and the gravel aquifer of variable thickness on the paper model. The horizontal scale, which needs to be used to determine they hydraulic gradient is given in the lower right hand corner of the model on the Sand/Gravel aquifer side.
Please remember the goal here is to have something that is useful but at the end of the day this is still a model (See Box quote)
The problem is given below:
1. Your boss gives you a potentiometric surface map of an aquifer (Figure A) and tells you that some tests have shown that the total discharge (Q) through the aquifer is 1,400,000 GPD. She also tells you that the effective porosity of the aquifer is 0.25. You are also given two conceptual models of what may be going on in the aquifer (Figure B, and C). Based on this information your boss wants you to answer the following questions.
A. What is the transmissivity of the gravel of the Sand/Gravel aquifer?
B. What is the transmissivity of the sand of the Sand/Gravel aquifer?
C. What is the transmissivity of the thick portion of the Gravel only aquifer?
D. What is the transmissivity of the thin portion of the Gravel only aquifer?
E. What is the specific discharge for the thick portion of the Gravel only aquifer?
F. What is the specific discharge for the thin portion of the Gravel only aquifer ?
G. What is the average linear velocity for the thick portion of the Gravel only aquifer?
H. What is the average linear velocity for the thin portion of the Gravel only aquifer?
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